buncha/code & dev/js-playground

JavaScript Playground

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JavaScript5 lines · 124 chars

const name = 'world';
console.log(`Hello, ${name}!`);

const sum = 2 + 2;
sum; // the last expression is shown as the result

const name = 'world';
console.log(`Hello, ${name}!`);

const sum = 2 + 2;
sum; // the last expression is shown as the result

Console

Output appears here. Edit the code and it runs automatically, or press Run.

Runs in a sandboxed Web Worker in your browser — nothing is uploaded, and your code is saved only on this device. The last expression's value is shown like a REPL; for top-level await, wrap your code in an async IIFE.

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About JavaScript Playground

A live JavaScript REPL in your browser — type code and see the result instantly. It runs your JavaScript automatically as you type and streams the console output, the value of the last expression, and any errors into a console pane, just like a developer tools panel. Console.log prints objects, arrays, Maps, Sets and circular references with a proper inspector (not JSON), and async output from setTimeout and promises streams in too. Your code runs in a sandboxed Web Worker, so an accidental infinite loop is terminated automatically instead of hanging the tab. Syntax-highlighted editor with line numbers, loadable examples, and everything stays on your device.

Everything happens on your device. Close the tab and it's gone.